1. Field of the Invention
This invention relates generally to orthodontic appliances, and more particularly concerns a Class II or III malocclusion correction device that applies low continuous force through the use of dual plunger piston type devices, whether the mouth is open or closed. The appliance attaches to the maxillary arch at the first molar and to the mandibular arch on the archwire in the cuspid or bicuspid area, either unilaterally or bilaterally.
2. Description of Related Art
Orthodontic appliances, such as brackets, buccal tubes and the like, are typically applied to teeth by adhering the appliances to the surface of the teeth. Such appliances typically include archwire portions for receiving an archwire and ligature elastic bands to provide corrective forces to straighten and reposition the teeth. Headgear mounting tubes can also be attached to the maxillary arch at about the first molar, for the mounting of corrective headgear to straighten and reposition the teeth. Such orthodontic appliances typically include a base portion adapted to conform to the shape of the teeth to which they are applied.
A Class I malocclusion typically occurs when the bite is satisfactory in that the upper or maxillary teeth line up with the lower or mandibular teeth, but individual teeth are crooked, crowded or turned. A Class II malocclusion, also called an xe2x80x9coverbite,xe2x80x9d or xe2x80x9cbuck teeth,xe2x80x9d occurs when the upper teeth project beyond the lower teeth. A Class III malocclusion, also called an xe2x80x9cunderbite,xe2x80x9d occurs when the lower teeth project beyond the upper teeth. Orthodontic appliances can be used to exert a force between an individual""s upper and lower sets of teeth to aid in correction of such malocclusions. While coil springs have been used to apply force for adjustment of malocclusions, coil springs can be uncomfortable for patients and can require the wearing of embarrassing and uncomfortable headgear, are subject to wear and breakage, and can limit the degree of a patient""s jaw movement.
There thus remains a need for a malocclusion correction device that is ideal for a non-compliant patient, allows flexibility in jaw movement, can be used on either left or right sides of a patient""s teeth, and can even be used unilaterally. It would be desirable to provide a malocclusion correction device for correction of Type II or III malocclusions, that eliminates the need for headgear, aids in midline correction, does not limit the patient""s range of motion of the lower jaw, and applies a constant force whether the patient""s mouth is open or closed, providing for a more predictable treatment time. The present invention meets these needs.
Briefly, and in general terms, the present invention provides for an orthodontic appliance for correction of Class II or III malocclusions, that allows a full range of motion and flexibility of jaw movement, applies a low continuous force through the use of two plunger piston type devices, whether the mouth is open or closed. The appliance of the present invention attaches to the maxillary arch at the first molar and to the mandibular arch on the archwire in the cuspid or bicuspid area, either unilaterally or bilaterally. The appliance can be used for either the left and right sides of the teeth of a patient, and can be used on one side alone, if desired. The appliance of the present invention eliminates the need for the use of headgear for correction of Class II or III malocclusions, and can used as an aid in midline corrections. With the orthodontic appliance of the invention, the duration of a course of orthodontic treatment for correction of Class II or III malocclusions can be more predictable than was heretofore possible.
The present invention accordingly provides for an orthodontic appliance for correction of Class II or III malocclusion of maxillary teeth and mandible teeth, with dual piston cylinders connectable between the maxillary teeth and mandible teeth. The orthodontic appliance comprises a first piston cylinder and a second piston cylinder connected together, with each piston cylinder having first and second ends. The first piston cylinder includes a first piston connecting rod slidably connected within the first piston cylinder and extending from the first end of the first piston cylinder, and the first piston cylinder biases the first piston connecting rod in a direction along the longitudinal axis. The second piston cylinder includes a second piston connecting rod slidably connected within the second piston cylinder and extending from the first end of the second piston cylinder, and the second piston cylinder biases the second piston connecting rod in a direction along the longitudinal axis of the second piston connecting rod, with the exterior ends of the first and the second piston connecting rods extending in opposing directions. In a presently preferred aspect, a first archwire is connected to the maxillary teeth, and a second archwire is connected to the mandible teeth. A first mounting element is connected to the exterior end of the first piston connecting rod for mounting the first piston connecting rod to the first archwire connected to the maxillary teeth, and a second mounting element is connected to the exterior end of the second piston connecting rod for mounting the second piston connecting rod to the second archwire connected to the mandibular teeth.
In a presently preferred embodiment, the first piston connecting rod is biased to extend toward the exterior end of the first piston connecting rod, and the second piston connecting rod is biased to extend toward the exterior end of the second piston connecting rod. In another presently preferred aspect of the invention, the first mounting element is connected to the exterior end of the first piston connecting rod by a ball and socket joint so as to be rotatable with respect to the first piston cylinder, and the second mounting element is connected to the exterior end of the second piston connecting rod by a ball and socket joint so as to be rotatable with respect to the second piston cylinder. In another presently preferred aspect, the first and second mounting elements comprise locking fasteners connectable to the first and second archwires, respectively.
In one currently preferred embodiment, the first piston cylinder comprises a first piston cylinder housing, a first compression spring disposed in the first piston cylinder dwelling, the interior end of the first piston connecting rod being connected to the first compression spring, the first piston connecting rod being slidable within the first piston cylinder housing along the longitudinal axis of the first piston connecting rod, the first compression spring biasing the first piston connecting rod to extend away from the first compression spring; and the second piston cylinder comprises a second piston cylinder housing, a second compression spring disposed in the second piston cylinder housing, the interior end of the second piston connecting rod being connected to the second compression spring, the second piston connecting rod being slidable within the second piston cylinder housing along the longitudinal axis of the second piston connecting rod, the second compression spring biasing the second piston connecting rod to extend away from the second compression spring.
These and other aspects and advantages of the invention will become apparent from the following detailed description and the accompanying drawings, which illustrate by way of example the features of the invention.